CardBus card instantly powers off my laptop

I got a USB 2.0 Cardbus card for my Gateway 600YG2. When I stick it in either PCMCIA slot, the computer powers off the instant it's seated. I tried suspending the PCMCIA slots before inserting it, and the computer still powered off.

When I insert it with the computer off and then turn it on, it powers off less than 10 seconds after the bootloader passes control to the OS kernel, before any logs get written.

The card says "Best connectivity" on it, and has 2 USB ports and a hole to plug in an optional AC adapter (sold separately).

This is the first time I've put a card in this computer. I don't have any other cards to try.

So.. could I have a bad card, or a bad computer, or what? What do I do?

BlueSloth

I just got back from the store where I bought the USB card. They tried it in 2 laptops at the store, and it worked. They said to come back tomorrow when the owner is there.

Last week I remembered that my first laptop, a 7 year old Dell, has an ethernet card in it that I know works. I dug it out and put the card in my Gateway, and it worked.

So, there's something about my particular computer that doesn't like that particular card. I don't think it's likely to be a software problem. I use Linux, and, unlike some other operating systems, Linux does not shut down the computer unless I tell it to. Actually, as far as I know, no OS will instantly cut power to the whole computer just because it sees a piece of hardware it doesn't like.

However, with a problem as unusual as mine, I shouldn't ignore a potential cause just because it's unlikely.

Here's some more possibly relevant information in case anyone wants to take on the challenge of figuring this out:

The speakers on the computer make interesting humming and buzzing noises that vary according to what the computer's doing. I figure the power supply must not be tightly regulated, or maybe there's a lot of resistance in the power supply circuits, and the CPU or something is causing voltage spikes when it draws current. Maybe a badly designed PCMCIA card will cause a big enough dip in the voltage when it first makes contact that things quit working. This is just a wild guess, I actually don't really know what I'm talking about here...

When the computer was less than a year old, and still running Windoze XP, it quit booting. The power would come on, but then it'd just sit there with a black screen and do nothing. I reseated the memory and everything else I could get to easily, and finally took it to a Gateway store and had them fix it. They never did tell me what was wrong.

It has suddenly shut down several times in the past. Those shutdowns were caused by either a fan problem (now solved) making it overheat, or me letting the battery completely die.

BlueSloth

I still haven't solved the problem, but here's another update.

I just now got around to finding a power supply for the USB card. I'd been dealing with college, and a hard drive failure..

Anyway, I got a DC adapter from Radio Shack, thinking that it might help somehow. With the computer off, I plugged the adapter into the card's DC input plug, put the card in a PCMCIA slot, plugged the adapter into a power strip, and turned on the computer. It started booting, then suddenly lost power, just like before.

Here's another little tidbit of information that's probably not relevant, but I'm going to mention it just in case: I have a Zip 250 drive plugged into one of the old "high speed" USB 1.1 ports on my port replicator. I also have a shredder in the same room, probably powered by the same circuit that the computer is plugged in to. Quite often when I turn the shredder off after shredding something, the Zip drive makes a loud noise. It's the same noise it makes when I plug it in, like it's initializing or calibrating or whatever it is that Zip drives do. I thought it was a weird coincidence at first, but it's been happening rather predictably.

I've thought about taking the computer apart and peeking inside, but I figure the chances of me actually finding something wrong that I can fix are quite small. Besides, last time I took a laptop apart and put it back together, I ended up with 13 left over pieces. It still works though.

BlueSloth